The invention relates to apparatus for electroplating the contact elements of encapsulated electronic components and like parts; it relates, more particularly, to means for conveying such components through a system composed of multiple surface treatment stations, including electroplating stations, suspended from an electrically conductive conveyor belt.
In the field of electronics it has been found advantageous to encapsulate delicate components--typically integrated circuit chips of various types--in electrically insulating bodies from which only contact elements, necessary to communicate with other portions of a completed circuit, protrude. It is particularly advantageous to create such insulating bodies by dipping the component to be protected into a ceramic slip and firing the ceramic material into a rigid protective body. Such ceramic encapsulated electronic components--known as sidebrazed ceramic packages, or C-dips for short--are particularly resistant to failure in environments which, because of chemical or thermal extremes, would affect the performance of unencapsulated components, or those whose protective sheaths are made from plastics or other less resistive materials.
A particular problem with such C-dip components relates to the relative mechanical fragility of the capsules during processing and handling operations subsequent to the firing of the ceramic sheaths. A serious problem exists with respect to the plating of the exterior contact elements--commonly with tin or precious metals, such as silver or gold--which is generally undertaken only after the components have successfully survived the encapsulating operations. Barrel plating and other methods which would subject the C-dips to severe mechanical stress are automatically foreclosed, and rack plating processes--requiring the manual placement of each component into plating baskets and their removal after plating is completed--are time-consuming and expensive.
The prior art has offered some solutions based on the entrainment of such parts on, or by, continuous conveyors of various types--including U.S. Patents to CURTIS (2,626,621), REID (3,066,091), GRIMALDI ET AL (3,878,062), WELTER (3,649,507), HELDER (4,032,414) and JOHNSON ET AL (4,508,611)--which failed to satisfactorily cure the handling and quality problems encountered in the electroplating--and in the associated surface treatment operations--the contact elements of sidebrazed ceramic packages and similar electronic components and their analogues, and found no wide acceptance in the practice of the art.